Extracorporeal membrane oxygenation (ECMO) has been used to treat refractory acute respiratory distress syndrome (ARDS) due to COVID-19. A study was conducted to explore outcomes of ECMO as a rescue therapy for ARDS due to COVID-19, focusing on the outcome differences between the first wave and the second wave.
In the study presented at CHEST 2021, researchers looked at adult patients with ARDS due to COVID-19 who were placed on ECMO. All adults placed on ECMO between April 2020 and March 2021 were identified within an approved database and included in this study. The patients were stratified as first wave patients (ECMO started on 04/2020-09/2020) and second wave patients (ECMO started on 11/2020-03/2021), as no ECMO was initiated during October 2020. Clinical characteristics and outcomes were compared between the two groups.
A total of 41 patients with COVID-19 on ECMO were identified. All ECMO was performed with venovenous ECMO; no venoarterial ECMO was performed. Among them, 28 patients (median age, 52 years; male, 68%) were stratified to the first wave and 13 patients (median age, 45 years; male, 69%) were stratified to the second wave. Pre-ECMO comorbidities were not significantly different between the two groups; however, pre-ECMO immunomodulators were more often given in the second wave (steroids 54% vs. 100%, P = 0.003; remdesivir 39% vs. 85%, P = 0.007), and second wave patients were more often placed in prone position before ECMO (11% vs. 85%, P < 0.001).
Findings indicated that the median length of ECMO was 14 days in first wave patients vs. 20 days in second wave patients (P = 0.728). ECMO mortality was greater in second wave patients compared with first wave patients (9/28, 32% in first wave vs. 9/13, 69% in second wave, P = 0.026). Other complications observed during ECMO included acute renal failure (39% vs. 38%, P = 0.960), sepsis (32% vs. 23%, P = 0.553), bacterial pneumonia (11% vs. 8%, P = 0.762), gastrointestinal bleed (21% vs. 15%, P = 0.650) and cerebral vascular accident (4% vs. 23%, P = 0.050).
“Despite improved pre-ECMO treatment, second wave patients with COVID-19 experienced higher mortality on ECMO than first wave patients,” said Rohit Reddy, BS, lead researcher and CHEST 2021 presenter. “More strict inclusion/exclusion criteria for ECMO may be necessary to improve outcomes.”